* sp-api: Support expanding the macro code
This pr introduces the `expander` crate to expand the generated source code into a file. This gives
better error reporting when trying to fix issues in the macro itself as Rustc will point to the line
in this file. The feature can be enabled by setting `SP_API_EXPAND=1` at compile time.
Besides that the generated code is changed to fix warnings in the exanped version.
* Fixes
* Runtime API versioning
Related to issue #11577
Add support for multiple versions of a Runtime API. The purpose is to
have one main version of the API, which is considered stable and
multiple unstable (aka staging) ones.
How it works
===========
Some methods of the API trait can be tagged with `#[api_version(N)]`
attribute where N is version number bigger than the main one. Let's call
them **staging methods** for brevity.
The implementor of the API decides which version to implement.
Example (from https://github.com/paritytech/substrate/issues/11577#issuecomment-1145347025):
```
decl_runtime_apis! {
#{api_version(10)]
trait Test {
fn something() -> Vec<u8>;
#[api_version(11)]
fn new_cool_function() -> u32;
}
}
```
```
impl_runtime_apis! {
#[api_version(11)]
impl Test for Runtime {
fn something() -> Vec<u8> { vec![1, 2, 3] }
fn new_cool_function() -> u32 {
10
}
}
}
```
Version safety checks (currently not implemented)
=================================================
By default in the API trait all staging methods has got default
implementation calling `unimplemented!()`. This is a problem because if
the developer wants to implement version 11 in the example above and
forgets to add `fn new_cool_function()` in `impl_runtime_apis!` the
runtime will crash when the function is executed.
Ideally a compilation error should be generated in such cases.
TODOs
=====
Things not working well at the moment:
[ ] Version safety check
[ ] Integration tests of `primitives/api` are messed up a bit. More
specifically `primitives/api/test/tests/decl_and_impl.rs`
[ ] Integration test covering the new functionality.
[ ] Some duplicated code
* Update primitives/api/proc-macro/src/impl_runtime_apis.rs
Code review feedback and formatting
Co-authored-by: asynchronous rob <rphmeier@gmail.com>
* Code review feedback
Applying suggestions from @bkchr
* fmt
* Apply suggestions from code review
Co-authored-by: Bastian Köcher <bkchr@users.noreply.github.com>
* Code review feedback
* dummy trait -> versioned trait
* Implement only versioned traits (not compiling)
* Remove native API calls (still not compiling)
* fmt
* Fix compilation
* Comments
* Remove unused code
* Remove native runtime tests
* Remove unused code
* Fix UI tests
* Code review feedback
* Code review feedback
* attribute_names -> common
* Rework `append_api_version`
* Code review feedback
* Apply suggestions from code review
Co-authored-by: Bastian Köcher <bkchr@users.noreply.github.com>
* Code review feedback
* Code review feedback
* Code review feedback
* Use type alias for the default trait - doesn't compile
* Fixes
* Better error for `method_api_ver < trait_api_version`
* fmt
* Rework how we call runtime functions
* Update UI tests
* Fix warnings
* Fix doctests
* Apply suggestions from code review
Co-authored-by: Bastian Köcher <bkchr@users.noreply.github.com>
* Apply suggestions from code review
Co-authored-by: Bastian Köcher <bkchr@users.noreply.github.com>
* Fix formatting and small compilation errors
* Update primitives/api/proc-macro/src/impl_runtime_apis.rs
Co-authored-by: Bastian Köcher <bkchr@users.noreply.github.com>
Co-authored-by: asynchronous rob <rphmeier@gmail.com>
Co-authored-by: Bastian Köcher <bkchr@users.noreply.github.com>
Co-authored-by: Bastian Köcher <info@kchr.de>
Przemek Rzad